Application Of Modified Magnetic Nanoparticles In The Extraction And Preconcentration Of Environmental Hormones

Environment hormones, as a type of chemical substrates affecting in vivo endocrine function, are widely distributed in nature. Being chemically stable and hard to decompose, they can accumulate and enter into human body through food chain, creating serious threat to human health. Since they have become one of the most serious global environment issues, analysis of environment hormones are of significant importance recently.In this work, different types of modified magnetic nanoparticles were synthesized and applied as absorbents in the extraction of environment hormones. Modified magnetic materials can make full use of the unique properties of the modified layer and the advantages of magnetic nanoparticles, thus contributing to high extraction efficiency. The application of magnetic materials made the pretreatment process simpler, faster and more efficient. The synthesized magnetic materials have been successfully used in the pretreatment of investigated analytes.Through microwave-assisted method, novel imidazole ionic liquids-immobilized magnetic nanomaterial (Fe3O4@SiO2@ILs) was prepared and applied in the extraction of sulfonylurea herbicides from tea samples. The sulfonylurea herbicides were preconcentrated through magnetic solid phase extraction and analyzed through high performance liquid chromatography (HPLC). Due to the ?-? interaction and structural similarity between sulfonylurea herbicides and imidazole ILs with tosylate anions, the magnetic material showed high selectivity upon different targets. Comparisons of extraction efficiency with conventional solid-phase extraction equipped with a commercial C18 cartridge were further performed. Experimental results suggested that this novel magnetic material, as an adsorbent, possessed higher extraction efficiency of extracting sulfonylurea-type environment hormones.Polymer ionic liquids modified polystyrene magnetic nanoparticles (PILs-PMNPs) were prepared through an emulsion polymerization method, and fully characterized with various techniques. Its application in extraction of plasticizers from beverages was investigated. More specifically, its extraction condition was optimized and ultra-high performance liquid chromatography (UPLC) analysis method was established. The extraction efficiency of the absorbents was significantly improved, benefiting from the good solubility of PILs and strong ?-? interaction between polystyrene and plasticizers. Comparisons of extraction efficiency with the polystyrene magnetic nanoparticles were further performed. Results demonstrated that poly ionic liquids modified polystyrene magnetic nanoparticles possessed better adsorption capability towards the trace phthalate esters analytes.